656
FXUS65 KBYZ 311904
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
104 PM MDT SUN MAY 31 2026
KEY MESSAGES
- SHOWERS TAPER OFF LATE THIS AFTERNOON THROUGH TONIGHT; SNOW
SHOWERS MAY AFFECT THE BEARTOOTH HIGHWAY ABOVE VISTA POINT
THROUGH THE EVENING.
- GRADUAL WARMING THIS WEEK, BUT WEATHER PATTERN REMAINS ACTIVE
WITH A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS.
DISCUSSION
THROUGH NEXT SUNDAY...
PRECIPITATION CONTINUES OVER MUCH OF THE REGION AS OF NOON BUT
STARTING TO SEE BREAKS ACROSS THE WEST (DOWNSLOPE EFFECTS). WE
REMAIN UNDER THE DIFFLUENT REGION OF THE UPPER LEVEL JET HOWEVER
SO THIS EVENT ISN'T FINISHED. OVER THE NEXT 12-18HRS THE TROF AXIS
WILL SLOWLY MIGRATE NORTHWARD AND PRECIP WILL GRADUALLY TAPER
OFF. LOOK FOR 0.20-0.60" OF ADDITIONAL RAINFALL FROM TREASURE AND
ROSEBUD COUNTIES EASTWARD, AND LESS TO THE WEST. REGARDING
CONVECTION THIS AFTERNOON/EVENING, NON-SEVERE T-STORMS ARE
POSSIBLE IN OUR FAR EAST AND OVER SOUTHERN MOUNTAINS & FOOTHILLS,
THE LATTER OF WHICH WILL BE UNDER THE PV AXIS AND COOLER TEMPS
ALOFT BY EVENING, AND AIDED BY A WEAK SECONDARY SHORTWAVE LIFTING
OUT OF SOUTHEAST ID, ON SOUTHERN FLANK OF MAIN UPPER LOW. SNOW
LEVEL AT OR ABOVE 10KFT SHOULD FALL TO NEAR 9.5KFT BY EVENING,
THUS SOME CONVECTIVE SNOW SHOWERS ARE EXPECTED OVER THE HIGH
ELEVATIONS OF THE BEARTOOTHS. WILL LET WINTER WX ADVISORY FOR
WINTRY TRAVEL IMPACTS OVER THE BEARTOOTH HIGHWAY CONTINUE, BUT
ACCUMS WILL BE MINIMAL.
AS PRECIP DISSIPATES AND SHIFTS NORTHWARD TONIGHT, THE DOWNSLOPE
WINDS SHOULD PREVENT A RISK OF FOG DESPITE THE RECENT RAINFALL,
WHICH HAS EXCEEDED 2" IN SOME AREAS.
SATELLITE IMAGERY SHOWS ANOTHER TRAILING WAVE OVER OR. THIS
FEATURE WILL PROVIDE SOME ASCENT WHICH ALONG WITH DIURNAL HEATING
WILL RESULT IN SCATTERED AFTERNOON/EVENING SHOWERS & T-STORMS ON
MONDAY. FOR THE MOST PART THIS ACTIVITY WILL BE NON-SEVERE, BUT
THERE ARE SIGNS THAT IF A SOUTHEASTERLY LOW LEVEL JET DEVELOPS BY
EVENING THE INCREASED SHEAR & INSTABILITY COULD SUPPORT A COUPLE
STRONGER CELLS IN SOUTHEAST MT (MAINLY IN POWDER RIVER & CARTER
COUNTIES). SOMETHING TO MONITOR.
UPPER LOW REMAINS OVER SOUTHERN SK TUE/WED, KEEPING US UNDER
CYCLONIC FLOW, THUS AT LEAST A LOW (20-30%) CHANCE OF SHOWERS AND
T-STORMS EACH DAY. THERE MAY BE A BRIEF RISK OF SEVERE STORMS IN
THE FAR EAST ON TUESDAY, BUT ALL INDICATIONS ARE THAT THE MUCH
MORE FAVORABLE ENVIRONMENT WILL RESIDE IN THE DAKOTAS. OTHERWISE,
THE AIR MASS IS LOOKING MORE STABLE WEDNESDAY SO THIS WILL BE THE
MORE BENIGN DAY.
WEATHER PATTERN REMAINS ACTIVE AND ANOTHER PACIFIC WAVE ARRIVES
THURSDAY. AS TEMPS WARM GRADUALLY THE NEXT FEW DAYS (LOW-MID 70S
MON-WED, 75-80F THU) AND WINDS SHIFT TO THE E-SE, IT COULD BE A
DAY TO WATCH FOR POTENTIAL SEVERE T-STORMS. THIS IS CERTAINLY A
SIGNAL AMONG AI CONVECTIVE MODELS AND ENSEMBLES SHOW A DISTINCT
INSTABILITY MAXIMUM ON THIS DAY. IF IT MATERIALIZES, THERE WOULD
BE A RISK OF HAIL ON THURSDAY.
BY THE END OF THE WORK WEEK, FLOW BACKS TO THE SW AHEAD OF THE
NEXT DEEPENING PACIFIC COAST TROF. FRIDAY IS LOOKING MOSTLY DRY
AND IT WILL BE WARMER (UPPER 70S TO MID 80S). TEMPS SHOULD PUSH
90F BY SATURDAY. AT SOME POINT OVER THE WEEKEND WE WILL SEE
CONVECTIVE POTENTIAL INCREASE WITH ENERGY EMERGING FROM THE
PACIFIC TROF, AND THIS COULD ALSO BE A TIME TO WATCH FOR SEVERE
POTENTIAL. IT WOULD APPEAR THAT WE ARE ENTERING OUR MORE ACTIVE
THUNDERSTORM SEASON. RECENT PRECIP HERE AND ACROSS THE HIGH PLAINS
WILL HELP KEEP BOUNDARY LAYER MOISTURE ELEVATED, AND PROMOTE
THUNDERSTORM ACTIVITY.
JKL
AVIATION
SHOWERS AND A FEW THUNDERSTORMS WILL DECREASE THIS EVENING AND
OVERNIGHT AS THEY LIFT NORTH. WINDS WILL ALSO DECREASE ACROSS MUCH
OF THE REGION TONIGHT. A FEW LOCATIONS SUCH AS K6S0, K1KM, AND
KBHK WILL CONTINUE TO SEE 20 KT WINDS OVERNIGHT. MONDAY WILL SEE
15-30% CHANCES FOR THUNDERSTORMS WITH THE POTENTIAL FOR WIND
GUSTS UP TO 40 KTS AND SMALL HAIL (<0.5 IN). THUNDERSTORM
POTENTIAL INCREASES IN THE AFTERNOON IN THE WEST AND MOVES EAST
THROUGH THE EVENING AND OVERNIGHT. TORGERSON
PRELIMINARY POINT TEMP/POPS
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 046/071 046/074 048/075 050/079 052/081 053/090 057/081
22/T 31/B 20/B 03/T 41/U 01/U 12/T
LVM 039/066 039/071 041/075 044/075 044/079 046/084 048/074
43/T 33/T 21/B 15/T 31/U 11/U 13/T
HDN 043/073 044/075 045/076 047/081 049/081 051/092 054/082
22/T 30/B 11/B 13/T 41/U 10/U 11/B
MLS 043/070 046/074 047/074 048/079 052/079 055/089 057/082
61/B 31/B 10/B 12/T 62/W 20/U 11/U
4BQ 044/072 048/075 048/074 050/079 052/079 054/088 058/082
22/T 32/T 31/B 24/T 52/W 10/U 11/U
BHK 040/071 045/075 045/075 046/077 050/077 051/085 056/083
50/B 55/T 41/B 12/T 53/W 20/U 11/N
SHR 038/072 040/074 043/074 044/078 045/079 048/089 050/080
52/T 22/T 23/T 24/T 33/T 11/U 01/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MDT TONIGHT
FOR ZONE 67.
WY...NONE.
WEATHER.GOV/BILLINGS
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